不同导程转子组合的强化传热实验研究

Experimental investigation on heat transfer enhancement of assembled rotors of different leads

以质量分数60%甘油水溶液为管程流体,将导程100 mm和400 mm的转子进行交错排列,对内置该组合转子的换热管进行了强化传热及阻力特性实验研究。为了保证实验方法和实验结果的准确性,在实验开始之前进行了光管实验验证。实验结果表明:导程交错2-6和导程交错1-3的2种方案的综合强化传热效果好,该2种方案的综合评价因子PEC值在1.4—1.8之间,而导程交错4-12的综合强化传热效果比较差,PEC值在1.3—1.6之间,不及导程全400 mm的PEC值,说明为了获得较好的综合强化传热效果,必须将大导程转子数量控制在小导程转子强旋流范围内,否则只会起到反作用。

The experiments on the heat transfer enhancement and friction characteristics of tubes inserted with assembled rotors of lead 100 mm and 400 mm were conducted,with 60% glycerin solution as tube-side working fluid. To ensure the reliability and accuracy of the experiment apparatus and methods,the validation experiment of smooth tube was carried out before the actual experiments. The experimental results reveal that the comprehensive thermal performance of schemes of interlaced number 2-6 and 1-3 is fine,whose performance evaluation criteria（ PEC） is between 1. 4-1. 8,while comprehensive thermal performance of scheme of interlaced number 4-12 is worse,and the performance evaluation criteria（ PEC） is between 1. 3-1. 6,less than that of scheme of lead 400 mm,which means that number of rotors of large lead ought to be limited at the scope of strong swirling flow of rotors of small lead to obtain better comprehensive thermal performance,otherwise counteraction would be got.